Data storage of data and information and search and retrieval of the stored information through a network interface are significant tasks performed by computer systems. These tasks are complicated by the number of different types of data storage sources or stores that are available and by the number of different types of applications that are available to access and search the data sources. Often, some of the data sources are incompatible with the search or access application, which makes the search and retrieval of the data and information stored on the incompatible data sources impossible. To access incompatible data sources, the application must incorporate the accessing and searching logic and codes of each data source type desired. Writing such code is usually more complex and requires more effort to program than other types of programming code. Each data source typically has a set of query languages or a search engine to perform information retrieval or searching. The languages or search engine are usually unique to each data source.
Additionally, searches performed on the Internet, such as a web-wide search, span millions of web pages. Another type of search is an enterprise-type search, which typically indexes a much smaller, but much more varied set of content types. The web-wide type searches are less specific than enterprises-type searches, and users or requesters performing enterprise-type searches typically require access to different types of data sources.
Attempts have been made to provide systems to retrieve or search information resident in multiple data sources. U.S. Pat. No. 5,634,053 issued 27 May 1997 to Noble et al. describes a federated information management (FIM) system and method for integrating data from multiple databases to provide users with access to a virtual database. The FIM system provides a uniform user interface, however, the multiple databases mentioned are of a similar type, specifically, database management system (DBMS).
International Patent Publication No. WO-A-00/75,849 published 14 Dec. 2000 to Lackey et al. discloses a middleware system that provides access to disparate data sources, such as relational and non-relational databases, multidimensional databases, objects and extensible mark-up language (XML) files. The system of WO-A-00/75,849 provides access to different types of data sources, but only configures the properties of the data source, which enables the application to create a connection for the data source without configuring the search and returnable attributes required for searching. In essence the system of WO-A-00/75,849 provides flexible connectivity to a single data source, but does not provide such flexible and configurable data retrieval from heterogeneous data sources.
Attempts also have been made to provide systems for querying heterogeneous data sources distributed over a network using context interchange. U.S. Pat. No. 5,953,716 issued 14 Sep. 1999 to Madnick et al. describes a system for querying disparate, heterogeneous data sources over a network that includes a request translator and a data translator. The request translator translates a request having an associated data context declared by the requester into a query having a second data context associated with it. The second context is also associated with the query and is declared by, at least one of the disparate data sources. This system also includes a data translator, which translates received data from the data context declared by the data source queried into the data context associated with the request. A related method for querying disparate data sources over a network is also described. The method includes the steps of translating a request having an associated data context into a query having a second data context. The second data context is associated with one of the disparate data sources to be queried. The method further includes translating data received from the data sources, from the data contexts associated with the data sources, into the data context associated with the request.
The above systems are unable to support different types of data sources and dynamically identify applicable types of data sources, or dynamically define the scope of a search.
Thus, a need exists for a method or a system to address the problems discussed above for data access, search, or retrieval from multiple heterogeneous data sources.